Modern electronic control units (ECU's) found in on- and off-road vehicles contain several inputs for communicating with various vehicle sensors. Vehicle sensors are often provided in embedded systems having a microprocessor and software. Due to the complexity and the number of sensors in many of these embedded systems, it is desirable for the ECU to determine when a sensor is malfunctioning. In some instances, a sensor may fail but still produce a valid in-range signal. Traditional methods of detecting sensor malfunction include voltage or current biasing and electronic keying. Biasing may involve biasing a line of an electrical connector with a voltage and detecting a failed sensor or sensor connector based on detection of an electrical abnormality. Electronic keying may involve grounding one or more lines of an electrical connector and detecting a failed sensor or damaged connector based on the detected grounding scheme of the lines of the electrical connector.
According to an embodiment of the present disclosure, a vehicle is provided including a chassis, a ground engaging mechanism configured to support the chassis, and an electric machine supported by the chassis. The electric machine includes at least one of a generator and a motor. A detector is configured to detect a speed of the electric machine. A controller coupled to the detector is configured to control the electric machine. The detector is configured to provide a frequency output to the controller representative of the detected speed of the electric machine and a diagnostic signal to the controller having a predetermined frequency. The detector automatically provides the diagnostic signal to the controller upon activation of the detector and prior to providing the frequency output to the controller. The controller is configured to detect a communication fault between the detector and the controller based on the diagnostic signal.
According to another embodiment of the present disclosure, a method of diagnosing sensor communication for a vehicle is provided. The method includes the step of providing a vehicle having a ground engaging mechanism and a motor configured to drive the ground engaging mechanism. The vehicle includes a control system including a controller and a detection system, and the controller is configured to control the motor. The detection system is coupled to the motor and is configured to provide motor speed feedback to the controller. The method includes the steps of activating the control system of the vehicle and generating a diagnostic signal with the detection system upon activation of the control system. The diagnostic signal has a predetermined frequency. The method further includes generating a frequency-based speed signal representative of the detected speed of the motor after generation of the diagnostic signal. The method further includes detecting a communication fault between the controller and the detection system based on a comparison of a detected frequency of the diagnostic signal with the predetermined frequency.
According to yet another embodiment of the present disclosure, a vehicle is provided including a chassis, a ground engaging mechanism supporting the chassis, and an electric machine. A machine control unit is configured to control the electric machine. The machine control unit includes a sensor configured to detect a speed of the electric machine. A controller in communication with the machine control unit is configured to provide a command to the machine control unit. The machine control unit is configured to provide a frequency output to the controller representative of the detected speed of the electric machine and a diagnostic signal to the controller having a predetermined frequency. The machine control unit generates the diagnostic signal upon the frequency output detected at the controller indicating an improper speed of the vehicle. The controller is configured to detect a communication fault based on the diagnostic signal.
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate exemplary embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.